9×7×3+5? =404 cubic centimeters

404÷(4? × 3. 14) = 2525/3 14 cm.

Second,

The radius of the bottom of A is twice that of B, so if the length is equal, the volume of A is twice, twice and four times the square of the volume of B.. After the length of B is twice that of A, the relationship between volumes will change, so 4÷2=2 times, the volume of A is twice that of B, and so is its weight.

2? ÷2=2 times

30×2=60 kg

Third,

(3÷2)? ×3. 14÷2=3.5325 square centimeters is a semicircle area with a diameter of 3 centimeters.

3×(3÷2)÷2=2.25 cm 2 is a triangle with a height of 1.5 cm (because the height of a triangle is the radius of a semicircle) and a base length of 3 cm.

3.5325-2.25= 1.2825 square centimeter semicircle area minus triangle area is half of the shadow (there are four shadows, here are two).

1.2825× 2 = total shadow area of 2.565 cm2.

I hope I can help you and wish you progress in your study ~